Читать книгу The Esophagus - Группа авторов - Страница 78

Currently, video‐fluoroscopic recording of a modified barium swallow is the diagnostic modality of choice for initial investigation of the patient with OPD. During this study, recordings of a variety of boluses with different consistencies and volumes are made for subsequent analysis. These recordings may be used subsequently for future comparisons to evaluate progress. This technique provides not only adequate information about the movement of the barium bolus through the aerodigestive tract and documents misdirection of the bolus into the airway, but also vital information about the anatomy and function of the individual anatomic components of the aerodigestive tract involved in swallowing [66, 67]. Additionally, this modality is used to evaluate the effect of various postural and breathing techniques on the efficiency, as well as safety, of swallowing [32, 68]. Normal and abnormal video‐fluoroscopic findings of swallowing have been published extensively [32, 38, 69]. On video‐fluoroscopy, abnormalities of the oral phase of swallowing may manifest themselves as inadequate clearance of the barium bolus from the mouth (leaving a barium residue behind), piece‐meal swallowing due to inadequate tongue function, or difficulty initiating the swallowing sequence due to impaired cognitive or neural function [32]. Patients with difficulty controlling the labial or facial muscles will not be able to hold the barium bolus in their anterior mouth and will end up drooling during swallow. Premature spilling of the oral contents into the pharynx before the pharyngeal phase is activated will catch the airway off guard and may result in pre‐deglutitive aspiration. This abnormality commonly occurs with impaired palatal and/or lingual control.

Abnormalities of the pharyngeal phase of swallowing documented by video‐fluoroscopy include concomitant absent or diminished upward/forward movement of the larynx and hyoid bone, indicating inadequate suprahyoid muscle contraction. This abnormality may be accompanied by entry of barium into the airway beyond the level of the true vocal cords (aspiration). An incompetent velopharyngeal closure mechanism, due to inadequate elevation and/or weak posterior movement of the palate and uvula, may result in regurgitation of the barium into the nasopharynx. This abnormality may develop after stroke, inflammatory disorders of striated muscles, or surgical excisions. Abnormalities of the oral phase of swallowing may or may not be accompanied by abnormalities of the pharyngeal phase of swallowing.

Abnormalities in transport function during oropharyngeal swallowing result in hypopharyngeal residue. Abnormal lingual, pharyngeal, or UES function, singularly or in combination, may be responsible. Unilateral involvement of the pharynx results in ipsilateral post‐deglutitive bulging of the pharyngeal wall and residue on the same side [29, 38].

Misdirection of the barium into the airway may be due to intrinsic abnormalities of the glottal adductor muscles, resulting in an ineffective glottal sphincteric mechanism or lack of coordination between glottal closure and transport function of the oropharynx, which is commonly seen in neurologically impaired patients.

Abnormal opening of the UES during swallowing, seen by video‐fluoroscopy, may be due to lack of or impairment of its relaxation, decreased UES compliance, or inadequate traction by the suprahyoid muscles. Correct diagnosis requires manometric evaluation of the UES for its resting pressure and its swallow‐induced relaxation. Diagnosis of cricopharyngeal achalasia cannot be made solely from its radiographic appearance.